Spray cooled electric furnace systems of the type disclosed in U.S. Pat. No. 4,715,042, 4,815,096 and 4,849,987 involve the spray cooling of furnace closure elements, e.g. roofs and side walls, which are unitary, i.e. formed into one piece. Due to the geometry of furnace electrodes and oxygen lances and the like, variations in heating of the furnace, occur and a particular relatively discrete region of the surface of a spray cooled closure element, e.g. a side wall, can be exposed to unusually high temperature and become thermally stressed with the risk of failure at such region. U.S. Pat. No. 5,327,453 describes a steel frame and copper plate assembly for use with unitary furnace closure elements to address locations of high thermal stress.
Since the furnace systems as above described have unitary, one-piece, carbon steel closure elements, it is not possible to use replaceable, removable customized sections to address the situation.